With recent increasing level of demand for advanced performance, plastics have been required to serve as a metal substitutes. For example, Patent Literature 1 discloses a resin composition capable of yielding a molded article having high levels of rigidity and elastic modulus, as a result of blending of a polyamide resin with a carbon fiber having a predetermined strength. Patent Literature 1 also describes that blending of a granular filler successfully reduced the surface roughness and waviness.
Patent Literature 2 describes a colored filament-reinforced pellet which contains a thermoplastic polymer resin, a fiber reinforcement having a length of approximately 5 mm or longer and 50 mm or shorter, and a pigment, wherein the addition quantity of the pigment is approximately 0.01% by weight or more and 5% by weight or less.
Patent Literature 3 discloses a thermoplastic resin composition configured by 100 parts by weight of a resin component which is composed of 40 to 98% by weight of a thermoplastic resin (A), and 60 to 2% by weight of a thermoplastic resin (B) having a softening point 17° C. or more lower than that of the thermoplastic resin (A), blended with 1 to 25 parts by weight of a carbon black (C), and 10 to 190 parts by weight of a fibrous filler (D).
Patent Literature 4 discloses a fiber-reinforced thermoplastic composite “A” configured by a thermoplastic resin, and a fiber reinforcement and a carbon black which are highly dispersed therein, the fiber reinforcement having an average diameter of 3 to 21 μm and an average length of 0.3 to 30 mm, the content of which being 5 to 80% by weight relative to the composite, the carbon black having a structure length in primary aggregate of 60 nm or shorter, and the content of which being 0.01 to 5% by weight relative to the composite.
Patent Literature 5 discloses a carbon filament-reinforced polyamide resin prepreg containing a polyamide resin and a carbon fiber, and the content of the carbon fiber being 40 to 80% by mass.